Electronic sign



FIG. 1 is a front view of an electronic sign, a new design;

FIG. 2 is a rear view thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a right view thereof; and,

FIG. 5 is a left side view thereof.

In the drawings, the broken lines represent features that form no part of the claimed design. 

The ornamental design for an electronic sign, as shown. 